[Plugin: LeagueManager] thumbnail creation for network

Hi guys!

I try to fix a bug, please support. While Adding New Team -> Uploading Logo for multisite blog, I met several warnings, logo is not converted, thumbnail not created…
any suggestions?

Warnings below:

Warning: Division by zero in C:\wordpress\wp-content\plugins\leaguemanager\lib\thumbnail.inc.php on line 216
Call Stack

Warning: imagecreatetruecolor() [function.imagecreatetruecolor]: Invalid image dimensions in C:\wordpress\wp-content\plugins\leaguemanager\lib\thumbnail.inc.php on line 321